The term "polyphenylene ether resin" is descriptive of a well known group of polymers that may be made by a variety of catalytic and non-catalytic processes. By way of illustration, certain of the polyphenylene ethers are disclosed in Hay, U.S. Pat. Nos. 3,306,874 and 3,306,875, and in Stamatoff, 3,257,357 and 3,257,358. In the Hay patents, the polyphenylene ethers are prepared by an oxidative coupling reaction comprising passing an oxygen-containing gas through a reaction solution of a phenol and a metal-amine complex catalyst. Other disclosures relating to processes for preparing polyphenylene ethers are found in Fox, U.S. Pat. No. 3,356,761; Sumitomo, U.K. Pat. No., 1,291,609; Bussink et al, U.S. Pat. Nos. 3,337,499; Blanchard et al, 3,219,626; Laakso et al, 3,342,892; Borman, 3,344,166; Horl et al, 3,384,619; Faurote et al, 3,440,217; and disclosures relating to metal based catalysts which do not include amines, are known from patents such as Wieden et al, U.S. Pat. No. 3,442,885 (copper-amidines): Nakashio et al, U.S. Pat. No. 3,573,257 (metal-alcoholate or phenolate); Kobayashi et al, U.S. Pat. No. 3,455,880 (cobalt chelates); and the like. In the Stamatoff patents, the polyphenylene ethers are produced by reacting the corresponding phenolate ion with an initiator, such as a peroxy acid salt, an acid peroxide, a hypophalite, and the like, in the presence of a complexing agent. Disclosures relating to non-catalytic processes, such as oxidation with lead dioxide, silver oxide, etc., are described in Price et al, U.S. Pat. No. 3,382,212. Cizek, U.S. Pat. No. 3,383,435 discloses compositions of polyphenylene ethers and styrene resins. All of the above-mentioned disclosures are incorporated herein by reference.
In Czechoslovakian Pat. No. 165,110 there are described compositions of a polyphenylene ether resin; polystyrene or high impact polystyrene; and either an ethylene-propylene copolymer polyisobutylene or an .alpha.-olefin copolymer. U.S. Pat. Nos. 3,943,191; 4,101,503; 4,101,504; 4,101,505 and 4,102,850 all disclose compositions that include a polyphenylene ether resin and an alkenyl resin that is modified with an interpolymerized EPDM rubber.
The applicants have found that when a composition of a polyphenylene ether, and an alkenyl aromatic resin is modified by the inclusion of a small quantity of an EPDM rubber, the resulting compositions have improved Izod and Gardner impact strength and ductility as compared to analogous compositions prepared with ethylene propylene rubber. The invention also includes compositions of a polyphenylene ether resin, a phosphate compound and an EPDM rubber and optionally a thermoplastic rubber.
Accordingly, it is a primary object of this invention to provide thermoplastic molding compositions of a polyphenylene ether resin, an alkenyl aromatic resin and an EPDM rubber.
It is also an object of this invention to provide a reinforced and flame retardant molding composition of a polyphenylene ether resin, an alkenyl aromatic resin and an EPDM rubber